CN110813911B

CN110813911B - Nuclear power plant and containment maintenance method thereof

Info

Publication number: CN110813911B
Application number: CN201911124734.XA
Authority: CN
Inventors: 周清利; 黄长添; 吴崇志; 王曦
Original assignee: Shanghai Nuclear Engineering Research and Design Institute Co Ltd
Current assignee: Shanghai Nuclear Engineering Research and Design Institute Co Ltd
Priority date: 2019-11-18
Filing date: 2019-11-18
Publication date: 2022-01-25
Anticipated expiration: 2039-11-18
Also published as: CN110813911A

Abstract

The invention relates to cleaning equipment for a nuclear power station containment, wherein an air circulation channel is arranged on the outer side of the containment, and the cleaning equipment comprises: a source of compressed air; a compressed air line; the purging ports are arranged adjacent to the outer surface of the containment vessel top head; and a purge control unit, wherein: the compressed air pipeline is communicated with a compressed air source and the plurality of purging ports, and the plurality of purging ports purge the outer surface of the head cover; the purge control unit is adapted to control a purge operation based on a purge port. The invention also relates to a nuclear power station with the cleaning equipment and a cleaning method for the containment vessel of the nuclear power station.

Description

Nuclear power plant and containment maintenance method thereof

Technical Field

The embodiment of the invention relates to the field of facility safety, in particular to cleaning equipment and method for a containment vessel of a nuclear power station and the nuclear power station with the cleaning equipment.

Background

During normal operation of the nuclear power plant (power operation, startup shutdown, or refueling), the passive containment cooling system (PCS) does not perform any function. The in-containment heat during normal operation of the nuclear power plant is rejected by a containment fan cooler of a containment circulating cooling system (VCS) to a central chilled water system (VWS).

Except for a mode specified by a power station technical specification, the PCS is in a standby state, and in addition to meeting the requirements of water content, chemical characteristics, temperature and periodic tests, the PCS especially provides the requirements of cleaning the surfaces of a water distribution hopper, a cofferdam and a safety shell so as to ensure that a passive containment cooling water tank sprays the outer surface of the top head by utilizing gravity drainage within 72 hours after a Design Basis Accident (DBA) occurs, the internal heat is conducted to the outer surface of the top head through a steel containment, and the drainage flowing through the outer surface of the top head is taken away in a convection heat exchange, radiation and evaporation mode.

Here, the water film distribution on the outer surface of the head is uniform and the coverage rate is required. Therefore, a water diversion hopper and a cofferdam are arranged on the top seal head of the containment vessel, so that the water film covering effect of water on the outer surface of the top seal head is improved, and the cooling capacity of the PCS is further improved. The PCS includes an air flow passage for creating a natural circulating air flow upward along the outer surface of the head, enhancing the evaporation rate of water (DBA-based) flowing over the outer surface of the head to reduce the pressure in the containment vessel, the air flow passage being normally open, the exhaust section being higher than the air inlet to enhance additional buoyancy to reduce the possibility of reverse air flow, during which time the air inlet and exhaust section should prevent icing, snow and foreign objects from blocking the air flow passage.

However, air can come in and out of the containment vessel and contact with the outer surface of the containment vessel top head, and dust carried by the atmosphere is accumulated on the surface of the containment vessel top head, so that the requirement of Design Basis Accident (DBA) that water films flowing through the outer surface of the top head are uniformly distributed cannot be met, and further the containment vessel cooling performance of the PCS can be affected.

In conclusion, the accumulation of atmospheric dust on the outer surface of the head cover is inevitable, and the cleanliness of the head cover is required so as to meet the design purpose.

The outer part of the conventional nuclear power containment is cleaned regularly through a water diversion hopper, a cofferdam facility to ensure the uniform distribution of water films flowing through the outer surface of the head and the coverage rate requirement of the water films; when the passive containment cooling auxiliary water tank is cleaned regularly, two PCS recirculating pumps are required to be connected in parallel to operate, the passive containment cooling auxiliary water tank or other water sources inside and outside a plant are conveyed to the water diversion hopper, and the outer surface of the containment, the cofferdam, the water diversion hopper and the like are cleaned. In addition, a small flange interface is arranged in a valve room in the steel dome and can be connected with a hose, and the external surface of the containment, a cofferdam, a water diversion hopper and the like can be washed for cleaning by utilizing a passive containment cooling auxiliary water tank water source. Need retrieve or other processings to the nonradioactive waste water that produces in above-mentioned cleaning process, whole cleaning process needs the cooperation of multiple operating personnel and loaded down with trivial details operation just can go on, and the process is loaded down with trivial details, has both received the time limitation, has also improved operating personnel intensity of labour and because of the error risk.

Disclosure of Invention

At present, the method for cleaning the facilities is complicated, the possibility of human errors exists, and an automatic dust cleaning system which is simple in system, convenient and fast to operate, capable of reducing human errors, capable of remotely monitoring, capable of cleaning in real time and capable of reducing labor intensity of workers is necessary to be provided in combination with the air pollution condition. The present invention has been made to solve at least one of the technical problems occurring in the prior art.

According to an aspect of an embodiment of the present invention, a cleaning device for a containment of a nuclear power plant is provided, in which an air circulation channel is provided outside the containment, the cleaning device includes:

a source of compressed air;

a compressed air line;

the purging ports are arranged adjacent to the outer surface of the containment vessel top head; and

a purging control unit for controlling the flow of the gas,

wherein:

the compressed air pipeline is communicated with a compressed air source and the plurality of purging ports, and the plurality of purging ports purge the outer surface of the head cover;

the purge control unit is adapted to control a purge operation based on a purge port.

Optionally, the monitoring unit is used for monitoring the dust deposition state of the outer surface of the head.

Optionally, the purge control unit controls the purge operation based on a monitoring signal from a monitoring unit.

Optionally, the cleaning device further comprises a data storage unit for storing the dust deposition data of the outer surface of the head enclosure obtained based on the monitoring unit.

Optionally, the monitoring unit comprises a plurality of monitoring units, and the monitoring units are uniformly spaced along the outer peripheral surface of the containment.

Optionally, the monitoring unit is arranged in a minimum circle water diversion hopper of the containment.

Optionally, the monitoring unit includes an image acquiring device for acquiring a deposition image or deposition data at a predetermined deposition position.

Optionally, the cleaning apparatus further comprises an ash deposition threshold value judging device which judges whether an ash deposition amount at a predetermined ash deposition position exceeds a threshold value based on the ash deposition image or the ash deposition data, and the purge control unit is adapted to start a purge operation based on the purge port if the ash deposition amount exceeds the threshold value.

Optionally, the ash deposition threshold value judging device judges whether the ash deposition amount at a plurality of predetermined points at predetermined ash deposition exceeds a threshold value based on the ash deposition image or the ash deposition data, and the purge control unit is adapted to start the purge operation based on the purge port if the ash deposition amount exceeds the threshold value.

Optionally, the monitoring unit further includes a dust deposition sampling device, and the image obtaining device obtains a dust deposition image or dust deposition data of the dust deposition sampling device.

Optionally, the dust deposition sampling device comprises a sampling surface and a sampling cover, the sampling surface is arranged in the sampling cover, and the sampling cover is in a cylindrical shape with an upper opening and a lower opening; the image acquisition device acquires a dust deposition image or dust deposition data of the sampling surface.

Optionally, the monitoring unit includes an optical sensor, the optical sensor includes a light emitter and a light receiver, the light emitter and the light receiver are respectively disposed at two sides of the predetermined ash deposition position in the horizontal direction, and the purge control unit is adapted to start the purge operation based on the purge port in a case where the ash deposition at the predetermined ash deposition position reaches a predetermined height so that a light path between the light receiver and the light emitter is blocked.

Optionally, the plurality of purge ports are arranged around the entire circumference of the outer surface of the head.

Optionally, the plurality of purge ports are connected to the underside of the steel dome.

Optionally, the plurality of purge ports comprises a plurality of purge port groups, each purge port group comprising a plurality of purge ports arranged around the entire circumference of the head enclosure outer surface.

Optionally, the compressed air source comprises a compressed air pipeline arranged outside the containment; or the source of compressed air comprises a compressed air tank or an air compressor. Alternatively, the air pressure of the compressed air source is in the range of 0.8MPa-2.5 Mp.

Optionally, the sweeping device further comprises an electric control valve arranged on the compressed air pipeline and used for adjusting and controlling the air flow flowing to the corresponding purging port, wherein: the purge control unit controls the electric control valve.

According to another aspect of an embodiment of the present invention, there is provided a nuclear power plant including:

a containment vessel;

the shielding wall is arranged around the containment and a gap is formed between the inner wall of the shielding wall and the outer wall of the containment; and

the cleaning device described above.

According to another aspect of the embodiments of the present invention, a maintenance method for a containment of a nuclear power plant is provided, in which an air circulation channel is provided outside the containment, the method includes the steps of:

a plurality of purging ports are arranged adjacent to the outer surface of the containment vessel top head; and

and introducing compressed air into the purging port to purge the outer surface of the head cover.

Optionally, the method further comprises the steps of: monitoring the dust deposition degree of the outer surface of the top head; and when the monitored ash deposition degree exceeds a threshold value, introducing compressed air into the purge port to purge.

Optionally, the method further comprises the steps of: historical monitoring data about the degree of dust deposition on the outer surface of the head is stored.

Optionally, the threshold is corresponding historical monitoring data; or the threshold value is a preset deposition thickness.

Drawings

These and other features and advantages of the various embodiments of the disclosed invention will be better understood from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate like parts throughout, and in which:

FIG. 1A is a block diagram of a nuclear power plant containment clean-up apparatus according to an exemplary embodiment of the present invention;

FIG. 1B is a block diagram of a nuclear power plant containment clean-up apparatus according to an exemplary embodiment of the present invention;

FIG. 1C is a block diagram of a nuclear power plant containment clean-up apparatus according to an exemplary embodiment of the present invention;

FIG. 1D is a block diagram of a nuclear power plant containment clean-up apparatus according to an exemplary embodiment of the present invention;

FIG. 2A is a schematic diagram of a monitoring unit of a nuclear power plant containment cleaning apparatus according to an exemplary embodiment of the present invention;

FIG. 2B is a schematic structural diagram of a monitoring unit of the nuclear power plant containment cleaning equipment according to an exemplary embodiment of the invention;

fig. 3 is a schematic view exemplarily showing the arrangement position of the cleaning equipment for the containment of the nuclear power plant according to the present invention.

Detailed Description

The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings. In the specification, the same or similar reference numerals denote the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the general inventive concept of the present invention and should not be construed as limiting the invention.

The general concept of the present invention is to replace the prior art water wash solution with a compressed air purge solution.

Fig. 1A is a schematic diagram of a nuclear power plant containment vessel cleaning apparatus according to an exemplary embodiment of the present invention. Fig. 3 is a schematic view schematically illustrating the arrangement position of the purging device for a containment vessel of a nuclear power plant according to the present invention, in which an air circulation passage 200 between a containment vessel 300 and a shield wall 400 of the nuclear power plant is also exemplarily illustrated.

As shown in fig. 1A and 3, a nuclear power plant containment vessel cleaning apparatus 100 (as shown in fig. 3, an air flow passage 200 is provided outside a containment vessel) includes:

a source of compressed air 110;

a compressed air line 120;

a plurality of purge ports 130 disposed adjacent to the containment vessel head external surface S; and

the purge control unit 140 is provided in the outside of the main body,

wherein:

the compressed air pipeline 120 is communicated with a compressed air source 110 and the plurality of purging ports 130, and the plurality of purging ports 130 purge the head external surface S;

the purge control unit 140 is adapted to control a purge operation based on a purge port.

It should be noted that the "purge operation based on the purge port" is not limited to controlling the purge port, but includes any operation of blowing out the compressed air from the purge port. Purging operations include, but are not limited to, opening and closing of a purge, adjustment of the amount of purge air, opening and closing of a purge valve (mentioned later).

In fig. 1A, only one purge port and one compressed air line are shown, but the present invention is not limited thereto, and the number of purge ports and compressed air lines may vary based on actual conditions.

In fig. 1A, compressed air may be used to purge or clean the air flow channels and clean the outer surface of the containment head based on the above-described purging device.

The cleaning can be performed automatically at regular intervals or can be manually started based on, for example, dust accumulation on the outer surface of the head.

In an embodiment of the invention, the compressed air source 110 may include a compressed gas line disposed outside the containment vessel (e.g., disposed at the steel dome 500); or the compressed air source 110 includes a compressed air tank or air compressor.

The air pressure of the compressed air source may be in the range of 0.8Mpa-2.5 Mp.

As shown in fig. 1A, the scavenging device 100 may further include an electrically-operated regulator valve 180 disposed on the compressed air line 120 for regulating and controlling the flow of air to the corresponding purge port, wherein: the purge control unit 140 controls the electric regulator valve 180. When the compressed air source is an air compressor, the electric control valve 180 may not be provided.

As shown in fig. 1B, in a further embodiment, the sweeping device 100 may further comprise a monitoring unit 150. The monitoring unit 150 may be used to monitor the soot deposition state of the head outer surface S.

The monitoring unit may be simply a camera unit (image acquiring means) which acquires an image of the dust deposit and then returns to the control room, and the operator determines whether the purging operation needs to be performed. In one embodiment, a dust accumulation alarm device may also be provided to alert an operator to perform a purge operation.

In further embodiments, the purge control unit 140 may automatically control the purge operation based on information from the monitoring unit. The purge control unit 140 may communicate directly with the monitoring unit 150, process the signals from the monitoring unit, and then perform a purge operation based on the results of the processing of the signals.

However, the purge control unit 140 may not have a processing function for the signal from the monitoring unit 150. As shown in fig. 1C, the sweeping apparatus 100 may be further provided with an ash deposition threshold value judging means 160 for processing the image signal or data signaled from the monitoring unit 150, judging whether the amount of ash deposition at the ash deposition exceeds a threshold value, and then signaling whether or how to perform the purge operation to the purge control unit 140 based on the judgment result. In a further embodiment, the soot threshold value judging means 160 may judge whether or not the amount of soot deposited at a plurality of predetermined points at a predetermined soot deposition exceeds a threshold value (see, for example, fig. 2A, in which there may be nine sampling points) based on the image signal or data from the monitoring unit 150. The threshold value may be a corresponding historical monitoring data, or may be a predetermined deposition thickness, in one embodiment. Fig. 2A is a schematic layout of a monitoring unit of the nuclear power plant containment vessel cleaning equipment according to an exemplary embodiment of the present invention. Fig. 2B is a schematic structural diagram of a monitoring unit of the nuclear power plant containment vessel cleaning device according to an exemplary embodiment of the present invention.

As shown in fig. 2B, the monitoring unit 150 further includes a deposited dust sampling device 152 in addition to the image obtaining device 151, and the image obtaining device 151 obtains a deposited dust image or deposited dust data of the deposited dust sampling device 152. As shown in fig. 2B, the dust collecting sampling device 152 includes a sampling surface 152A and a sampling cover 152B, the sampling surface 152A is disposed in the sampling cover 152B, and the sampling cover 152B is a cylinder with an upper opening and a lower opening; the image acquiring device 151 acquires a dust image or dust data of the sampling surface 152A. In fig. 2B, the sampling hood 152B is transparent or has an opening for the image acquisition device to acquire images. As can be appreciated, the position of the image acquisition device 151 may vary as long as a deposited image or deposited data can be obtained. The provision of the sampling cap 152B helps prevent the dust deposition on the sampling surface from being disturbed due to the turbulent air flow.

Although not shown, the monitoring unit includes an optical sensor including a light emitter and a light receiver respectively disposed at both sides of a predetermined ash deposition in a horizontal direction, and the purge control unit is adapted to initiate a purge operation based on the purge port in a case where the ash deposition at the predetermined ash deposition reaches a predetermined height such that a light path between the light receiver and the light emitter is blocked.

As shown in fig. 1D, the sweeping apparatus may further include a data storage unit 170 for storing the soot deposition data of the outer surface of the head based on the monitoring unit. The stored dust deposition data can be historical data of a certain time period for subsequent retrieval and research; or may be threshold data in a normal range, for example, provided to the deposited ash threshold determination device 160. The data storage unit 170 may be part of the purge control unit 140 or may be provided separately from the purge control unit 140.

As shown in fig. 2A, the monitoring unit 150 includes a plurality of monitoring units that are evenly spaced circumferentially around the outer surface of the header. Four are shown in fig. 2A, but the present invention is not limited thereto and the number thereof may vary.

Fig. 3 is a schematic view exemplarily showing the arrangement position of the cleaning equipment for the containment of the nuclear power plant according to the present invention. As shown in fig. 3, the plurality of purge ports are disposed near the outer surface of the head, as shown in fig. 3, with the purge ports suspended from a steel dome 500. The location of the monitoring unit and the location of the purge port may be adjacent to each other, and accordingly, in one embodiment, the monitoring unit is also disposed within the containment's smallest circle of the water diversion buckets.

As can be appreciated, the plurality of purge ports are disposed around the entire circumference of the head outer surface.

As can be appreciated, the plurality of purge ports includes a plurality of groups of purge ports, each group of purge ports including a plurality of purge ports arranged around an entire circumference of the head outer surface.

As can be appreciated, the monitoring unit may also monitor the results after purging.

Correspondingly, the embodiment of the invention also provides a maintenance method for the containment of the nuclear power station, wherein an air circulation channel is arranged outside the containment, and the method comprises the following steps:

a plurality of purging ports are arranged adjacent to the outer surface of the top head; and

In a further embodiment, the maintenance method further comprises the steps of: monitoring the dust deposition degree of the outer surface of the top head; and

and when the monitored ash deposition degree exceeds a threshold value, introducing compressed air into the purging port to purge.

Based on the above, in the invention, the image data can be collected by the image acquisition device for the dust deposition condition on the safe outer surface, the image data is collected and/or compared and analyzed, the signal is transmitted to the control room, and the operation engineer remotely controls the electric control valve according to the set threshold value to realize the purging of the outer surface of the containment vessel top head, thereby meeting the design requirement. The purged gas may flow out of the atmosphere outlet with the atmosphere entering the air flow channel, and larger particles may fall based on gravity. Based on the scheme, the water film can be uniformly distributed under the design benchmark accident condition, and the sewage treatment work under the original design is also avoided.

Accordingly, an embodiment of the present invention also provides a nuclear power plant, referring to fig. 3, including:

a containment vessel 300;

the shielding wall 400 is arranged around the containment and an air circulation channel 200 is arranged between the inner wall of the shielding wall and the outer wall of the containment; and

the cleaning apparatus 100 described above.

Although embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims

1. A nuclear power plant, comprising:

a containment vessel comprising a head;

the shielding wall is arranged around the containment, and a first air circulation channel is formed between the inner wall of the shielding wall and the outer wall of the containment;

the steel dome and the top head define a second air circulation channel therebetween;

the monitoring unit is used for monitoring the dust deposition state of the outer surface of the top head; and

containment cleanup equipment, the cleanup equipment comprising:

a source of compressed air;

a compressed air line;

a purging control unit for controlling the flow of the gas,

wherein:

the compressed air pipeline is communicated with a compressed air source and the plurality of purge ports;

the purge control unit is adapted to control a purge operation based on a purge port;

the first air circulation channel comprises a U-shaped channel, the inlet of the U-shaped channel is communicated with the atmosphere, and the outlet of the U-shaped channel is communicated with the second air circulation channel;

the plurality of purge ports are arranged around the entire circumference of the head outer surface, the plurality of purge ports being disposed in the second air circulation channel and connected to the underside of the steel dome to purge the head outer surface;

the monitoring unit and the purging port are located adjacent to each other, and the monitoring unit is arranged in a water diversion bucket of a minimum circle of the containment.

2. The nuclear power plant of claim 1 wherein:

the purge control unit controls the purge operation based on a monitoring signal from a monitoring unit.

3. The nuclear power plant as recited in claim 1 further comprising:

and the data storage unit is used for storing the dust deposition data of the outer surface of the head based on the monitoring unit.

4. The nuclear power plant of claim 1 wherein:

the monitoring unit comprises a plurality of monitoring units which are uniformly arranged around the outer surface of the head in a circumferential direction at intervals.

5. The nuclear power plant of claim 1 wherein:

the monitoring unit includes an image acquisition device for acquiring a deposition image or deposition data at a predetermined deposition position.

6. The nuclear power plant of claim 5 wherein:

the cleaning apparatus further includes an ash deposition threshold value judging device that judges whether an ash deposition amount at a predetermined ash deposition location exceeds a threshold value based on the ash deposition image or ash deposition data, and the purge control unit is adapted to start a purge operation based on the purge port in the case where the ash deposition amount exceeds the threshold value.

7. The nuclear power plant of claim 6 wherein:

the ash deposition threshold judging device judges whether the ash deposition amount of a plurality of predetermined points at predetermined ash deposition exceeds a threshold value based on the ash deposition image or the ash deposition data, and the purging control unit is adapted to start a purging operation based on the purging port if the ash deposition amount exceeds the threshold value.

8. The nuclear power plant of claim 5 wherein:

the monitoring unit further comprises a dust deposition sampling device, and the image acquisition device acquires a dust deposition image or dust deposition data of the dust deposition sampling device.

9. The nuclear power plant of claim 8 wherein:

the dust deposition sampling device comprises a sampling surface and a sampling cover, wherein the sampling surface is arranged in the sampling cover, and the sampling cover is in a cylindrical shape with an upper opening and a lower opening;

the image acquisition device acquires a dust deposition image or dust deposition data of the sampling surface.

10. The nuclear power plant of claim 1 wherein:

the monitoring unit comprises an optical sensor which comprises a light emitter and a light receiver, the light emitter and the light receiver are respectively arranged at two sides of a preset dust deposition position in the horizontal direction, and the purging control unit is suitable for starting purging operation based on the purging opening under the condition that the dust deposition at the preset dust deposition position reaches a preset height so that a light path between the light receiver and the light emitter is blocked.

11. The nuclear power plant of claim 1 wherein:

the plurality of purge ports comprises a plurality of purge port groups, each purge port group comprising a plurality of purge ports arranged around the entire circumference of the head enclosure outer surface.

12. The nuclear power plant of claim 1 wherein:

the compressed air source comprises a compressed air pipeline arranged outside the containment; or

The compressed air source comprises a compressed air tank or an air compressor.

13. The nuclear power plant of claim 12 wherein:

the air pressure of the compressed air source is in the range of 0.8Mpa-2.5 Mp.

14. The nuclear power plant as recited in claim 1 further comprising:

electric control valve, set up on compressed air pipeline for adjust and control the air flow that the flow direction corresponds the purge port, wherein: the purge control unit controls the electric control valve.

15. A containment maintenance method of a nuclear power plant according to any one of claims 1 to 14, comprising the steps of:

16. The method of claim 15, further comprising the step of:

monitoring the dust deposition degree of the outer surface of the top head; and

17. The method of claim 16, further comprising the step of:

historical monitoring data about the degree of dust deposition on the outer surface of the head is stored.

18. The method of claim 16 or 17, wherein:

the threshold is corresponding historical monitoring data; or

The threshold is a predetermined deposition thickness.